Display device

ABSTRACT

An electroluminescent device includes a lower structure including an emission area and a peripheral area, a flexible encapsulating multilayer, and a touch panel including a touch electrode. The emission area includes an electroluminescent unit including a lower electrode disposed directly on an insulating film, an intermediate film, and an upper electrode disposed on the intermediate film. The peripheral area includes an inorganic surface portion substantially surrounding the emission area, various terminals, and wires. A lower surface of the flexible encapsulating multilayer and an upper surface of the inorganic surface portion each include only one or more inorganic materials in direct contact with each other.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority from and the benefit of Korean PatentApplication No. 10-2017-0034710, filed on Mar. 20, 2017, which is herebyincorporated by reference for all purposes as if fully set forth herein.

BACKGROUND Field

The invention relates generally to a display device having an integratedtouch screen display, and, more particularly, to a display device withan integrated touch display including a thin film encapsulationstructure.

Discussion of the Background

Among various types of display devices, a display device using aself-luminous is element generally has a fast response speed and candisplay a moving picture. Also, since a self-luminous element emitslight by itself, a display device including a self-luminous element hasa wide viewing angle and can achieve high luminance. Thus, a displaydevice including a self-luminous element has been in the spotlight as anext-generation display device.

An electroluminescent unit using a self-luminous element typicallyincludes a pixel electrode, an opposing electrode, and anelectroluminescent layer interposed between the pixel electrode and theopposing electrode. However, an electroluminescent unit is generallyvery sensitive to moisture, oxygen, and the like. For example, when theelectroluminescent unit contacts moisture, oxygen, and the like, displayquality may be deteriorated due to damage to the electroluminescentunit. Therefore, a thin film encapsulation structure is typically usedas a sealing process for blocking external moisture, oxygen, and/and thelike from entering the electroluminescent layer of theelectroluminescent unit.

Meanwhile, recent consumer demands often require display devices to beflexible and bendable and have an input unit capable of receiving auser's command, such as a touch screen panel, in addition to an outputfunction for displaying an image.

The above information disclosed in this Background section is only forenhancement of understanding of the background of the inventiveconcepts, and, therefore, it may contain information that does not formthe prior art that is already known in this country to a person ofordinary skill in the art.

SUMMARY

Applicants have discovered that integrating a touch panel in a displaydevice having flexible films instead of upper and lower substrate canresult in deterioration of the thin is film encapsulating structure,which can produce corresponding deterioration of display quality.Display devices constructed according to the principles of the inventionare capable of easily integrating a touch panel on a thin filmencapsulation structure and minimizing the risk of deterioration ofencapsulating structures that protect the light emitting unit.Therefore, display quality may increase. In one particularlyadvantageous design, the encapsulation structure may be formed by aflexible encapsulation multilayer with direct bonding between inorganicmaterials.

Additional aspects will be set forth in the detailed description whichfollows, and, in part, will be apparent from the disclosure or may belearned by practice of the inventive concepts.

Aspects of the present disclosure provide a display device in which atouch panel is easily integrated on a thin film encapsulation structurewithout a substantial deterioration of encapsulating characteristics ofthe thin film encapsulation structure.

According to an aspect of the invention, an electroluminescent devicemay comprise a lower structure, a flexible encapsulation multilayer, anda touch panel. The lower structure may have an emission area and aperipheral area surrounding the emission area and may comprise aninsulation film and an electroluminescent unit having a lower electrodedisposed on the insulation film, an intermediate film disposed on thelower electrode, and an upper electrode disposed on the intermediatefilm. The flexible encapsulation multilayer may be disposed on theemission area and the peripheral area of the lower structure and mayinclude at least three layers. The touch panel may be disposed on theflexible encapsulation multilayer and may have a touch electrode. Theperipheral area may include a lower electrode power supply terminal, alower electrode power supply wire electrically connecting the lowerelectrode to the lower electrode power supply terminal, an upperelectrode power supply terminal, an upper electrode power supply wireelectrically connecting the upper electrode to the upper electrode powerterminal, a touch terminal, and a touch wire electrically connecting thetouch electrode to the touch terminal. The flexible encapsulationmultilayer may include a lower surface comprising only one or moreinorganic materials. The peripheral area may include an inorganicsurface portion substantially surrounding the emission area, may bedisposed outside the upper electrode in a plan view, and may compriseonly one or more inorganic materials. An entire of the inorganic surfaceportion may directly contact the lower surface of the flexibleencapsulation multilayer. The lower structure may include a lowerencapsulating inorganic film horizontally expanding below a surface ofthe lower structure to vertically correspond to the emission area andthe peripheral area. A portion of the lower structure disposed betweenthe lower encapsulating inorganic film and the entire of the inorganicsurface portion may comprise only one or more inorganic materials. Thetouch wire may comprise a first portion overlapping the lower electrodepower supply wire and a second portion overlapping the upper electrodepower supply wire.

In exemplary embodiments of the invention, the upper electrode powersupply wire may include an auxiliary upper electrode extending along aperiphery of the emission area to electrically contact a bottom surfaceof the upper electrode. The lower structure may further comprise aperipheral circuit disposed under the auxiliary upper electrode in theperipheral area. A portion of the touch wire may extend substantiallyalong the periphery of the emission area and may overlap both theauxiliary upper electrode and the peripheral circuit.

In exemplary embodiments of the invention, widths of the portions of thetouch wires may decrease in a direction away from the emission area.

In exemplary embodiments of the invention, the peripheral area mayfurther include an auxiliary touch wire electrically connected to thetouch wire and overlapping the portion of the touch wire.

In exemplary embodiments of the invention, at least one of the lowerelectrode power supply terminals, at least one of the touch terminals,and at least one of the upper electrode power supply terminals may bedisposed in a terminal area of the peripheral area. The peripheral areamay include a bendable area extending between the emission area and theterminal area. At least one of the lower electrode power supply wire,the upper electrode power supply wire, and the touch wire may include aconductive bridge for transmitting an electrical signal through thebendable area. The conductive bridge may be formed in a different layerfrom the at least one of the lower electrode power supply wire, theupper electrode power supply wire, and the touch wire including theconductive bridge.

In exemplary embodiments of the invention, the touch wire further maycomprise a third portion overlapping the upper electrode power supplywire. The first portion of the touch wire may be disposed between thesecond and third portions of the touch wire.

In exemplary embodiments of the invention, the third portion of thetouch wire may overlap an end portion of the upper electrode powersupply wire.

In exemplary embodiments of the invention, the lower electrode may bedisposed directly on a top surface of the insulation film. The entire ofthe inorganic surface portion may be disposed to be relatively lowerthan the top surface of the insulation film. The inorganic surfaceportion may have at least a region including a plurality of inorganicsurface branches which are spaced apart from each other. The peripheralarea may further include an organic surface portion disposed between theinorganic surface branches. The organic surface portion may comprise anorganic material and substantially surround the emission area. Theorganic surface portion is substantially surrounded in a plan view by adirect contact interface between the inorganic surface portion and thelower surface of the flexible encapsulation multilayer. The inorganicsurface branches may include an outer inorganic surface branch disposedrelatively outer than the organic surface portion and an inner inorganicsurface branch disposed relatively inner than the organic surfaceportion. The upper electrode power wire may comprise a bus wireextending on a top surface of the inorganic insulating film along aperiphery of the emission area and an auxiliary upper electrode whichextends on side and top surfaces of the insulation film along theperiphery of the emission area to electrically contact both a topsurface of the bus wire and a bottom surface of the upper electrode. Theinner inorganic surface branch may include at least a portion of a topsurface of the auxiliary upper electrode to have a height relativelygreater than a height of the outer inorganic surface branch. A portionof a surface of the bus wire may directly contact the lower surface ofthe flexible encapsulation multilayer. The portion of the surface of thebus wire may be relatively farther than the organic surface portion fromthe emission area.

In exemplary embodiments of the invention, the electroluminescent devicemay be capable of being flexed, bent, folded, rolled, or stretched by anend user.

In exemplary embodiments of the invention, the inorganic surface portionmay include at least two stepped surface portions each including a topsurface portion of the inorganic insulating film, a side surface portionof the bus wire, and a top surface portion of the bus wire. The bus wiremay have an outer edge portion and an inner edge portion opposite to theouter edge portion. The outer edge portion of the bus wire may berelatively farther than the inner edge portion of the bus wire from theemission area. The outer edge portion of the bus wire may be disposedunder the bottom surface of the flexible encapsulation multilayer andmay be not in direct contact with the bottom surface of the flexibleencapsulation multilayer.

In exemplary embodiments of the invention, the inorganic surface portionmay further include at least two stepped surface portions each includinga top surface portion of the inorganic insulating film, a side surfaceportion of the auxiliary upper electrode, and a top surface portion ofthe auxiliary upper electrode. The auxiliary upper electrode may have anouter edge portion and an inner edge portion opposite to the outer edgeportion. The outer edge portion of the auxiliary upper electrode may berelatively farther than the inner edge portion of the auxiliary upperelectrode from the emission area. The outer edge portion of theauxiliary upper electrode may be disposed under the bottom surface ofthe flexible encapsulation multilayer and may be not in direct contactwith the bottom surface of the flexible encapsulation multilayer.

In exemplary embodiments of the invention, the inorganic surface portionmay further include at least two stepped surface portions each includinga top surface portion of the bus wire, a side surface portion of theauxiliary upper electrode, and a top surface portion of the auxiliaryupper electrode. The auxiliary upper electrode may have an outer edgeportion and an inner edge portion opposite to the outer edge portion.The outer edge portion of the auxiliary upper electrode may berelatively farther than the inner edge portion of the auxiliary upperelectrode from the emission area. The outer edge portion of theauxiliary upper electrode may be disposed under the bottom surface ofthe flexible encapsulation multilayer and may be not in direct contactwith the bottom surface of the flexible encapsulation multilayer.

In exemplary embodiments of the invention, the inorganic surface portionmay further include at least two stepped surface portions each includinga top surface portion of the inorganic insulating film, a side surfaceportion of the auxiliary upper electrode, and a top surface portion ofthe auxiliary upper electrode. The inorganic surface portion may furtherinclude at least two stepped surface portions each including a topsurface portion of the bus wire, a side surface portion of the auxiliaryupper electrode, and a top surface portion of the auxiliary upperelectrode. The auxiliary upper electrode may have an outer edge portionand an inner edge portion opposite to the outer edge portion. The outeredge portion of the auxiliary upper electrode may be relatively fartherthan the inner edge portion of the auxiliary upper electrode from theemission area. The outer edge portion of the auxiliary upper electrodemay be disposed under the bottom surface of the flexible encapsulationmultilayer and may be not in direct contact with the bottom surface ofthe flexible encapsulation multilayer.

In exemplary embodiments of the invention, the portion of the surface ofthe bus wire, which directly contacts the lower surface of the flexibleencapsulation multilayer, may be included in the outer inorganic surfacebranch.

In exemplary embodiments of the invention, at least one of the lowerelectrode power supply terminals, at least one of the touch terminals,and at least one of the upper electrode power supply terminals may bedisposed in a terminal area of the peripheral area and may havesubstantially the same heights to be electrically connected to oneexternal circuit board.

In exemplary embodiments of the invention, the at least one of the touchterminals may be disposed between the at least one of the lowerelectrode power supply terminals and the at least one of the upperelectrode power supply terminals.

In exemplary embodiments of the invention, the peripheral area mayinclude a bendable area extending between the emission area and theterminal area. The touch wire may is not overlap the lower electrodepower supply wire and the upper electrode power supply wire in thebendable area.

In exemplary embodiments of the invention, a size of the touch terminalmay be relatively less than a size of the lower electrode power supplyterminal, or a size of the upper electrode power supply terminal.

In exemplary embodiments of the invention, at least one of the lowerelectrode power supply terminal and the upper electrode power supplyterminal may be disposed in a power terminal area of the peripheral areaand may be electrically connected to a first external circuit board. Thetouch terminal may be disposed in a touch terminal area of theperipheral area and may be electrically connected to a second externalcircuit board. The power terminal area and the touch terminal area maybe disposed at a side of the lower structure and may not overlap eachother in a plan view. The first external circuit board and the secondexternal circuit board may be disposed at the side of the lowerstructure and may not overlap each other in a plan view. s A directionin which the first external circuit board is attached to the at leastone of the lower electrode power supply terminal and the upper electrodepower supply terminal may be the same as a direction in which the secondexternal circuit board is attached to the touch terminal. The flexibleencapsulation multilayer may include a first inorganic layer, an organiclayer disposed on the first inorganic layer, and a second inorganiclayer disposed on the organic layer. The touch terminal area may notoverlap the organic layer in a plan view.

In exemplary embodiments of the invention, at least one of the lowerelectrode power supply terminal and the upper electrode power supplyterminal may be disposed in a power terminal area of the peripheral areato be electrically connected to a first external circuit board. Thetouch terminal may be disposed in a touch terminal area of theperipheral area to be electrically connected to a second externalcircuit board. The power terminal area and the touch terminal area maybe disposed at a side of the lower structure and may not overlap eachother in a plan view. The first external circuit board and the secondexternal circuit board may be disposed at the side of the lowerstructure and may not overlap each other in a plan view. A direction inwhich the first external circuit board is attached to the at least oneof the lower electrode power supply terminal and the upper electrodepower supply terminal may be opposite to a direction in which the secondexternal circuit board is attached to the touch terminal. The flexibleencapsulation multilayer may include a first inorganic layer, an organiclayer disposed on the first inorganic layer, and a second inorganiclayer disposed on the organic layer. The touch terminal area may notoverlap the organic layer in a plan view.

The foregoing general description and the following detailed descriptionare exemplary and explanatory and are intended to provide furtherexplanation of the claimed subject matter.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the inventive concepts, and are incorporated in andconstitute a part of this specification, illustrate exemplaryembodiments of the inventive concepts, and, together with thedescription, serve to explain principles of the inventive concepts.

FIG. 1 is a plan view of an exemplary embodiment of a display deviceconstructed according to the principles of the invention.

FIG. 2 is a plan view of an exemplary embodiment of a display deviceconstructed according to the principles of the invention.

FIG. 3 is a plan view of a touch panel of FIG. 2.

FIG. 4 is a cross-sectional view taken along line I-I′ of FIGS. 1 and 2.

FIG. 5 is a schematic view showing an exemplary embodiment of a displaydevice constructed according to the principles of the invention.

FIG. 6 is an enlarged view of portion “A” of FIG. 5.

FIG. 7 is an enlarged view of area “B” of FIG. 5.

FIG. 8 is an enlarged view of area “C” of FIG. 5.

FIG. 9 is a schematic view showing an exemplary embodiment of a displaydevice constructed according to the principles of the invention.

FIG. 10 is a schematic view illustrating an inorganic surface portion ofFIG. 9.

FIG. 11 is a schematic view showing an exemplary embodiment of a displaydevice constructed according to the principles of the invention.

FIG. 12 is a schematic view showing an exemplary embodiment of a displaydevice constructed according to the principles of the invention.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

In the following description, for the purposes of explanation, numerousspecific details are set forth in order to provide a thoroughunderstanding of various exemplary embodiments. It is apparent, however,that various exemplary embodiments may be practiced without thesespecific details or with one or more equivalent arrangements. In otherinstances, well-known structures and devices are shown in block diagramform in order to avoid unnecessarily obscuring various exemplaryembodiments.

In the accompanying figures, the size and relative sizes of layers,films, panels, regions, etc., may be exaggerated for clarity anddescriptive purposes. Also, like reference numerals denote likeelements.

When an element or layer is referred to as being “on,” “connected to,”or “coupled to” another element or layer, it may be directly on,connected to, or coupled to the other element or layer or interveningelements or layers may be present. When, however, an element or layer isreferred to as being “directly on,” “directly connected to,” or“directly coupled to” another element or layer, there are no interveningelements or layers present. For the purposes of this disclosure, “atleast one of X, Y, and Z” and “at least one selected from the groupconsisting of X, Y, and Z” may be construed as X only, Y only, Z only,or any combination of two or more of X, Y, and Z, such as XYZ, XYY, YZ,and ZZ. Like numbers refer to like elements throughout. As used herein,the term “and/or” includes any and all combinations of one or more ofthe associated listed items.

Although the terms first, second, etc. may be used herein to describevarious elements, components, regions, layers, and/or sections, theseelements, components, regions, layers, and/or sections should not belimited by these terms. These terms are used to distinguish one element,component, region, layer, and/or section from another element,component, region, layer, and/or section. Thus, a first element,component, region, layer, and/or section discussed below could be termeda second element, component, region, layer, and/or section withoutdeparting from the teachings of the present disclosure.

Spatially relative terms, such as “beneath,” “below,” “lower,” “above,”“upper,” and the like, may be used herein for descriptive purposes, and,thereby, to describe one element or feature's relationship to anotherelement(s) or feature(s) as illustrated in the drawings. Spatiallyrelative terms are intended to encompass different orientations of anapparatus in use, operation, and/or manufacture in addition to theorientation depicted in the drawings. For example, if the apparatus inthe drawings is turned over, elements described as “below” or “beneath”other elements or features would then be oriented “above” the otherelements or features. Thus, the exemplary term “below” can encompassboth an orientation of above and below. Furthermore, the apparatus maybe otherwise oriented (e.g., rotated 90 degrees or at otherorientations), and, as such, the spatially relative descriptors usedherein interpreted accordingly.

The terminology used herein is for the purpose of describing particularembodiments and is not intended to be limiting. As used herein, thesingular forms, “a,” “an,” and “the” are intended to include the pluralforms as well, unless the context clearly indicates otherwise. Moreover,the terms “comprises,” “comprising,” “includes,” and/or “including,”when used in this specification, specify the presence of statedfeatures, integers, steps, operations, elements, components, and/orgroups thereof, but do not preclude the presence or addition of one ormore other features, integers, steps, operations, elements, components,and/or groups thereof.

Various exemplary embodiments are described herein with reference tosectional illustrations that are schematic illustrations of idealizedexemplary embodiments and/or intermediate structures. As such,variations from the shapes of the illustrations as a result, forexample, of manufacturing techniques and/or tolerances, are to beexpected. Thus, exemplary embodiments disclosed herein should not beconstrued as limited to the particular illustrated shapes of regions,but are to include deviations in shapes that result from, for instance,manufacturing. For example, an implanted region illustrated as arectangle will, typically, have rounded or curved features and/or agradient of implant concentration at its edges rather than a binarychange from implanted to non-implanted region. Likewise, a buried regionformed by implantation may result in some implantation in the regionbetween the buried region and the surface through which the implantationtakes place. Thus, the regions illustrated in the drawings are schematicin nature and their shapes are not intended to illustrate the actualshape of a region of a device and are not intended to be limiting.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this disclosure is a part. Terms,such as those defined in commonly used dictionaries, should beinterpreted as having a meaning that is consistent with their meaning inthe context of the relevant art and will not be interpreted in anidealized or overly formal sense, unless expressly so defined herein.

As used herein, the term of “comprising only an inorganic material”means that it comprises only one or more inorganic materials, but itdoes not mean that it comprises only one s inorganic material.

Also, the term of “comprising only an organic material” means that itcomprises only one or more organic materials, but it does not mean thatit comprises only one organic material. The term of “‘element’ portion”means at least a portion of the entire ‘element.’ For example, theclaimed term of “an inorganic surface portion” means at least a portionof the entire inorganic surface. Counting the number of ‘element’portions is possible when the ‘element’ portions are separated from eachother in a plan view such that merging the ‘element’ portions into one‘element’ portion is not possible.

In embodiments of the present disclosure, the term of “surrounding” or“substantially surrounding” includes not only contiguously surroundingbut also discontiguously surrounding. The term of “contiguously” issubstantially the same as the term of “continuously.” The term of“discontiguously” is substantially the same as the term of“discontinuously.”

Hereinafter, various examples (exemplary embodiments) will be describedwith reference to the accompanying drawings.

FIG. 1 is a plan view of an exemplary embodiment of a display deviceconstructed according to the principles of the invention. FIG. 2 is aplan view of an exemplary embodiment of a display device constructedaccording to the principles of the invention. FIG. 3 is a plan view of atouch panel of FIG. 2. FIG. 4 is a cross-sectional view taken along lineI-I′ of FIGS. 1 and 2.

Referring to FIGS. 1 to 4, each display device 1000 and 1000_a includesa substrate 101, a pixel thin film transistor (PC-TFT) array formed onthe substrate 101, an electroluminescent unit EU, and a flexibleencapsulation multilayer 200 for encapsulating the electroluminescentunit EU.

The substrate 101 may support the entire display device 1000 and 1000_aand maintain rigidity. The substrate 101 may comprise a transparentinsulating material and may have a substantially flat top surface. Forexample, the substrate 101 may comprise glass. However, the inventiveconcepts are not limited thereto and the substrate 101 may comprise aplastic material, such as polyethersulphone (PES), polyacrylate (PAR),and the like. Alternatively, the substrate 101 may comprise an opaquematerial, such as metal or carbon fiber. In order to construct aflexible display device, the substrate 101 may comprise a flexibleplastic material, such as a polyimide (PI) film.

The substrate 101 is divided into a display area DA and a peripheralarea PA1 to PA4 around the display area DA. The display area DA maydisplay an image and is disposed at the center of the substrate 101. Theperipheral area PA1 to PA4 may not display an image and is disposed atthe edge of the substrate 101 to surround the display area DA.

The peripheral area includes a first peripheral area PA1, a secondperipheral area PA2, a third peripheral area PA3, and a fourthperipheral area PA4. More specifically, as shown in FIGS. 1 and 2, adirection extending rightward is defined as a first direction x1, adirection extending leftward is defined as a second direction x2, adirection extending upward is defined as a third direction y1, and adirection extending downward is defined as a fourth direction y2. Thefirst direction x1 and the second direction x2 may be opposite to eachother. The third direction y1 and the fourth direction y2 may beopposite to each other. One of the first direction x1 and the seconddirection x2 and one of the third direction y1 and the fourth directiony2 may be perpendicular to each other.

The first peripheral area PA1 is disposed adjacent to the outside of alower structure 100 in the first direction x1. The second peripheralarea PA2 is disposed adjacent to the outside of the lower structure 100in the second direction x2. The third peripheral area PA3 is disposedadjacent to the outside of the lower structure 100 in the thirddirection y1. The fourth peripheral area PA4 is disposed adjacent to theoutside of the lower structure 100 in the fourth direction y2.

In the display area DA, a plurality of electroluminescent units EU,which emit light for displaying an image are disposed for respectivepixels. In the first to fourth peripheral areas PA1, PA2, PA3, and PA4,an upper electrode power supply wire 901 is formed to apply an electricsignal or power to an upper electrode 191 of the electroluminescent unitEU. The upper electrode power supply wire 901 includes a bus wire 155and an auxiliary upper electrode 172. Hereinafter, components disposedin the display area DA and the first to fourth peripheral areas PA1,PA2, PA3, and PA4 will be described in the order in which they may besequentially formed on the substrate 101.

A buffer film 111 is formed on the substrate 101. The buffer film 111may make the upper surface of the substrate 101 smooth and may block thepenetration of impurities. The buffer film 111 may be a multilayer or asingle layer and may comprise an inorganic material. Examples of theinorganic material may comprise silicon oxide (SiOx), siliconoxynitride, silicon nitride (SiNx), and a combination thereof. Thebuffer film 111 may be formed by various deposition methods. The bufferfilm 111 may be omitted if desired.

A pixel circuit C1 is formed on the buffer film 111. The pixel circuitC1 includes at least one pixel thin film transistor (PC-TFT). The pixelthin film transistor (PC-TFT) is electrically connected to theelectroluminescent unit EU to drive the electroluminescent unit EU. Thepixel circuit C1 may further include at least one capacitor.

The pixel thin film transistor (PC-TFT) is a top gate type TFT in whichan active layer 112, a gate electrode 131, a source electrode 156 a, anda drain electrode 156 b are sequentially formed. However, the inventiveconcepts are not limited thereto and various types of pixel thin filmtransistors (PC-TFTs), such as a bottom gate type, may be employed.

The active layer 112 is formed on the buffer film 111. The active layer112 includes a semiconductor material. Examples of the semiconductormaterial may include amorphous silicon or poly crystalline silicon.However, the inventive concepts are not limited thereto and the activelayer 112 may comprise an oxide semiconductor material. Examples of theoxide semiconductor material may include G—I—Z—O[(In2O3)_(a)(Ga2O3)_(b)(ZnO)_(c)] (a, b, and c are real numberssatisfying the conditions of a≥0, b≥0, c>0, respectively). The activelayer 112 may include, in addition to GIZO, an oxide of a materialselected from among 12-, 13-, and 14-group metallic elements, such aszinc (Zn), indium (In), gallium (Ga), tin (Sn), cadmium (Cd), germanium(Ge), and hafnium (Hf), or a combination thereof. The active layer 112includes a source region 112 a and a drain region 112 c in contact withthe source electrode 156 a and the drain electrode 156 b, respectively.The active layer 112 includes a channel region 112 b disposed betweenthe source region 112 a and the drain region 112 c. When the activelayer 112 includes amorphous silicon or polycrystalline silicon, thesource region 112 a and the drain region 112 c may be doped withimpurities, if necessary.

A gate insulating film 121 is formed on the active layer 112. The gateinsulating film 121 may be a multilayer or a single layer and maycomprise an inorganic material, such as silicon oxide, siliconoxynitride, and/or silicon nitride. The gate insulating film 121 mayinsulate the active layer 112 from the gate electrode 131.

The gate electrode 131 is formed on the gate insulating film 121. Thegate electrode 131 is connected to a gate line (not shown) for applyingan on/off signal to the pixel s thin film transistor (PC-TFT). The gateelectrode 131 may comprise a metal material having a relatively lowresistance. The gate electrode 131 may be a multilayer or a single layerand may comprise a conductive material. Examples of the conductivematerial may include molybdenum (Mo), aluminum (Al), copper (Cu),titanium (Ti), and the like.

An interlayer insulating film 141 is formed on the gate electrode 131.The interlayer insulating film 141 may insulate the gate electrode 131from the source and drain electrodes 156 a and 156 b. The interlayerinsulating film 141 may be a multilayer or a single layer and maycomprise an inorganic material, such as a metal oxide and a metalnitride. Specific examples of the inorganic material may include siliconoxide (SiO2), silicon nitride (SiNx), silicon oxynitride (SiON),aluminum oxide (Al2O3), titanium oxide (TiO2), tantalum is oxide(Ta2O5), hafnium oxide (HfO2), zinc oxide (ZrO2), or a combinationthereof

The source electrode 156 a and the drain electrode 156 b are formed onthe interlayer insulating film 141. The source electrode 156 a and thedrain electrode 156 b are in contact with the source region 112 a andthe drain region 112 c of the active layer 112, respectively, throughcontact holes formed through the gate insulating film 121 and theinterlayer insulating film 141.

A planarization film 161 is formed on the pixel thin film transistor(PC-TFT). The planarization film 161 may be a single layer or amultilayer and may comprise an organic material. The organic materialmay be a general purpose polymer. Examples of the general purposepolymer may comprise polymethylmethacrylate (PMMA), polystyrene (PS), apolymer derivative having a phenol group, an acrylic polymer, an imidepolymer, an arylether polymer, an amide polymer, a fluorine polymer, ap-xylene polymer, a vinyl alcohol polymer, or a combination thereof. Theplanarization film 161 may reduce or eliminate a step caused by thepixel thin film transistor (PC-TFT) array and makes the top surfacesubstantially flat, thereby preventing or minimizing the occurrence ofdefects in the electroluminescent unit EU due to unevenness at itsbottom portion. Further, the planarization film 161 may function as aninsulating film that blocks electrical connection between the componentsseparated by the planarization film 161.

The electroluminescent unit EU is formed on a portion of the uppersurface of the planarization film 161 corresponding to the display areaDA. The electroluminescent unit EU includes a lower electrode 171 formedon the planarization film 161, the upper electrode 191 facing the lowerelectrode 171, and an electroluminescent layer EL interposed between thelower and upper electrodes 171 and 191. The electroluminescent layer ELmay include an organic material. The display devices 1000 and 1000_a maybe classified into a bottom emission type, a top emission type, and adual emission type according to the emission direction of theelectroluminescent unit EU. In the bottom emission type, the lowerelectrode 171 is provided as a transparent or semi-transparent electrodefor transmitting light and the upper electrode 191 is provided as areflective electrode for reflecting light. In the top emission type, thelower electrode 171 is provided as a reflective electrode and the upperelectrode 191 is provided as a transparent or semi-transparentelectrode. In the dual emission type, both of the lower electrode 171and the upper electrode 191 may be transparent or semi-transparentelectrodes.

When the lower electrode 171 functions as an anode, the lower electrode171 may include a conductive material having a relatively high workfunction. Examples of the conductive material may comprise indium tinoxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium oxide(In2O3), indium gallium oxide (IGO), aluminum zinc oxide (AZO), or acombination thereof. The lower electrode 171 may be patterned into anisland shape corresponding to each pixel. Further, the lower electrode171 may be connected to the drain electrode 156 b of the pixel TFT(PC-TFT) to receive a current.

Meanwhile, a pixel defining layer (PDL) 181 is formed on the lowerelectrode 171 and covers the lower electrode 171. The pixel defininglayer 181 may comprise one or more organic insulating materials.Examples of the one or more organic insulating materials may comprisepolyimide, polyamide, acrylic resin, benzocyclobutene, phenol resin, ora combination thereof. The pixel defining layer 181 may be formed by aspin coating method, and the like. A predetermined opening for defininga pixel is formed on the pixel defining layer 181. Theelectroluminescent layer EL is formed at least in a region defined bythe opening. In some exemplary embodiments, the pixel defining layer 181is used to form a light emitting layer by a solution technique, such asan ink jet and nozzle printing method, and includes a partition having arelatively high height.

The electroluminescent layer EL may include a low molecular organicmaterial or a polymer organic material that emits red, green, or bluelight. A hole transport layer (HTL) and/or a hole injection layer (HIL)may be disposed between the electroluminescent layer EL and the lowerelectrode 171. Further, an electron transport layer (ETL) and/or anelectron injection layer (EIL) may be disposed between theelectroluminescent layer EL and the upper electrode 191. Various layersother than the hole injection layer (HIL), the hole transport layer(HTL), the electron transport layer (ETL), and the electron injectionlayer (EIL) may be stacked as needed.

Although the electroluminescent layer EL is described as being formedfor each pixel such that red, green, and blue light may be emittedindividually from each pixel and a pixel group for emitting red, green,and blue light may form one unit pixel, however, the inventive conceptsare not limited thereto and, thus, the electroluminescent layer EL maybe formed in common throughout the pixel. For example, a plurality ofelectroluminescent layers EL emitting red, green, and blue light may bevertically stacked or mixed to form white light. The combination ofcolors for emitting white light is not limited thereto. In this case, acolor conversion layer or a color filter for converting the emittedwhite light into a predetermined color may be separately provided.

The upper electrode 191 may comprise a conductive inorganic material.When the upper electrode 191 functions as a cathode, the upper electrode191 may comprise Al, Mg, Ag, and the like having a relatively small workfunction. The upper electrode 191 may be formed as a common electrodeover the entire display area DA. In this case, the upper electrode 191may be formed by an evaporation process that does not damage theelectroluminescent layer EL. The polarities of the lower electrode 171and the upper electrode 191 may be opposite to each other.

The upper electrode 191 may be connected to the upper electrode powersupply wire 901 disposed in the first to fourth peripheral areas PA1,PA2, PA3, and PA4 to receive an electrical signal or power. The upperelectrode power supply wire 901 includes the bus wire 155 and theauxiliary upper electrode 172.

The bus wire 155 applies the electric signal or power supplied from theoutside to the upper electrode 191. Therefore, the bus wire 155comprises a conductive inorganic material through which a current mayflow easily and may be formed to have a single layer or a multilayerstructure. Examples of the conductive inorganic material may comprisealuminum (Al), platinum (Pt), palladium (Pd), silver (Ag), magnesium(Mg), gold (Au), nickel (Ni), neodymium (Nd), iridium (Ir), chromium(Cr), calcium (Ca), molybdenum (Mo), titanium (Ti), tungsten (W), copper(Cu), or a combination thereof. The bus wire 155 is formed on theinterlayer insulating film 141. The bus wire 155 may be formed at thesame time when the source electrode 156 a and the drain electrode 156 bof the pixel thin film transistor (PC-TFT) are formed. In this case, thebus wire 155 may comprise the same conductive inorganic material as thesource electrode 156 a and the drain electrode 156 b.

The bus wire 155 should be electrically connected to the upper electrode191. However, the bus wire 155 and the upper electrode 191 are spacedapart from each other because the bus wire 155 and the upper electrode191 are formed on different layers. Therefore, the auxiliary upperelectrode 172 may electrically connect the bus wire 155 and the upperelectrode 191.

The auxiliary upper electrode 172 is in contact with the bus wire 155and the upper electrode 191 to transmit the electric signal or powersupplied from the bus wire 155 to the upper electrode 191. The auxiliaryupper electrode 172 may function as a bridge, or a link. Therefore, theauxiliary upper electrode 172 comprises a conductive inorganic materialthrough which a current may flow easily and may be formed to have asingle layer or a multilayer structure. Examples of the conductiveinorganic material may comprise aluminum (Al), platinum (Pt), palladium(Pd), silver (Ag), magnesium (Mg), gold (Au), nickel (Ni), neodymium(Nd), iridium (Ir), chromium (Cr), calcium (Ca), molybdenum (Mo),titanium (Ti), tungsten (W), copper (Cu), or a combination thereof. Theside surfaces of the planarization film 161 are disposed in the first tofourth peripheral areas PA1, PA2, PA3, and PA4. The auxiliary upperelectrode 172 is disposed along the side surfaces and the upper surfaceof the planarization film 161. According to an exemplary embodiment, theauxiliary upper electrode 172 may be formed together with the lowerelectrode 171 by using the same material as the lower electrode 171.

The auxiliary upper electrode 172 may extend along the periphery of thedisplay area DA. Specifically, the auxiliary upper electrode 172 has ashape surrounding or substantially surrounding the display area DA inthe first to fourth peripheral areas PA1, PA2, PA3, and PA4 to prevent adynamic voltage (IR) drop. As used herein, the term of “surrounding” issynonymous with “substantially surrounding” with respect to the shape ofthe auxiliary upper electrode 172 and refers to completely surroundingor partially surrounding, provided the configuration prevents orsignificantly reduces an IR drop. In order to increase the contact areabetween the auxiliary upper electrode 172 and the bus wire 155, the buswire 155 may also extend along the periphery of the display area DA inthe first to fourth peripheral areas PA1, PA2, PA3, and PA4.Specifically, the bus wire 155 may have a shape substantiallysurrounding the display area DA in the first to fourth peripheral areasPA1, PA2, PA3, and PA4.

The flexible encapsulation multilayer 200 is formed over the entiresurface of the substrate 101 to cover all of the display area DA and thefirst to fourth peripheral areas PA1, PA2, PA3, and PA4. Alternatively,the flexible encapsulation multilayer 200 may be formed on the substrate101 and cover all of the display area DA and at least a part of thefirst to fourth peripheral areas PA1, PA2, PA3, and PA4. The flexibleencapsulation multilayer 200 protects the electroluminescent unit EUfrom external moisture, oxygen, and the like. The flexible encapsulationmultilayer 200 may include a first inorganic layer 211, an organic layer212 on the first inorganic layer 211, and a second inorganic layer 213on the organic layer 212. Here, the organic layer 212 may have asubstantially flat upper surface such that the second the secondinorganic layer 213 disposed thereon has a substantially flat area FA.

However, the flexible encapsulation multilayer 200 is not limited to astructure having three stacked layers as shown in the FIG. 4. Theflexible encapsulation multilayer 200 may be formed by sequentiallystacking a first inorganic layer, a first organic layer, a secondinorganic layer, a second organic layer, and a third inorganic layerfrom the top of the electroluminescent unit EU. Here, the first organiclayer may have a relatively less area than the second inorganic layerand the second organic layer may have a relatively less area than thethird inorganic layer. Still alternatively, the flexible encapsulationmultilayer 200 may be formed by sequentially stacking a first inorganiclayer, a first organic layer, a second inorganic layer, a second organiclayer, a third inorganic layer, a third organic layer, and a fourthinorganic layer from the top of the electroluminescent unit EU. In thiscase, the first organic layer may the display area DA and the first tofourth peripheral areas PA1, PA2, PA3, and PA4 be completely coveredwith the second inorganic layer, the second organic layer may becompletely covered with the third inorganic layer and the third organiclayer may be completely covered with the fourth inorganic layer. Assuch, the area of the third inorganic layer is relatively wider than theareas of the first inorganic layer, the first organic layer, the secondinorganic layer, and the second organic layer, so that the thirdinorganic layer may cover the edges of the first inorganic layer, thefirst organic layer, the second inorganic layer, and the second organiclayer.

As described above, the flexible encapsulation multilayer 200 may havevarious structures and the lower surface of the flexible encapsulationmultilayer 200 may comprise only one or more inorganic materials.

The flexible encapsulation multilayer 200 may protect theelectroluminescent unit EU of the display area DA from external moistureand/or oxygen, even when the lower structure 100 is encapsulated by theflexible encapsulation multilayer 200 alone. That is, without using anyadditional encapsulation member for preventing penetration of moistureand/or oxygen in addition to the flexible encapsulation multilayer 200,the flexible encapsulation multilayer 200 alone may encapsulate theelectroluminescent unit EU to provide a reliable display device capableof preventing display defects caused by infiltration of externalmoisture and/or oxygen. The flexible encapsulation multilayer 200 mayinclude a plurality of films. However, the “flexible encapsulationmultilayer 200” may alternatively include a single film having anexcellent encapsulating ability.

The first to fourth peripheral areas PA1, PA2, PA3, and PA4 include aninorganic surface portion IS, which may have a substantially looped orclosed shape, for example, which contiguously surrounds the display areaDA. The inorganic surface portion IS directly contacts the lower surfaceof the flexible encapsulation multilayer 200 (e.g., the lower surface ofthe first inorganic layer 211). Since the inorganic surface portion ISincludes only one or more inorganic materials and the lower surface ofthe flexible encapsulation multilayer 200 (e.g., the lower surface ofthe first inorganic layer 211) also includes only one or more inorganicmaterials, a direct bonding between the inorganic surface portion IS andthe lower surface of the flexible encapsulation multilayer 200 is aninorganic-inorganic direct bonding.

The inorganic surface portion IS may be disposed in the first to fourthperipheral areas PA1, PA2, PA3, and PA4 and may have a shapecontiguously surrounding the display area DA as described above. Thatis, the inorganic surface portion IS may have a substantially closedshape such that the display area DA is disposed inside the inorganicsurface portion IS.

The inorganic surface portion IS may include only one inorganicmaterial. Alternatively, the inorganic surface portion IS may include aplurality of inorganic materials. The inorganic material constitutingthe inorganic surface portion IS may originate from at least one of, forexample, the buffer film 111, the gate insulating film 121, and theinterlayer insulating film 141. That is, a surface portion of the bufferfilm 111, a surface portion of the gate insulating film 121, and/or asurface portion of the interlayer insulating film 141 may be included inthe inorganic surface portion IS. In this case, the inorganic materialconstituting the inorganic surface portion IS may be silicon nitride, orsilicon oxynitride which have a relatively low moisture and oxygenpermeability. Further, the inorganic material constituting the inorganicsurface portion IS may originate from the bus wire 155 and/or theauxiliary upper electrode 172. That is, a surface portion of the buswire 155 and/or a surface portion of the auxiliary upper electrode 172may be included in the inorganic surface portion IS. In this case, theinorganic material constituting the inorganic surface portion IS may bea conductive inorganic material. Examples of the conductive inorganicmaterial may include aluminum (Al), platinum (Pt), palladium (Pd),silver (Ag), magnesium (Mg), gold (Au), nickel (Ni), neodymium (Nd),iridium (Ir), chromium (Cr), calcium (Ca), molybdenum (Mo), titanium(Ti), tungsten (W), copper (Cu), or a combination thereof.

The lower structure 100 may include a lower encapsulating inorganic filmhorizontally expanding below the surface portion of the lower structure100 to vertically correspond to the display area DA and the first tofourth peripheral areas PA1, PA2, PA3, and PA4. A portion of the lowerstructure 100 disposed between the inorganic surface portion IS and thelower encapsulating inorganic film may include only one or moreinorganic materials. The lower encapsulating inorganic film may be, forexample, the buffer film 111, the gate insulating film 121, or theinterlayer insulating film 141. Here, the lower encapsulating inorganicfilm may include silicon nitride, or silicon oxynitride which have arelatively low moisture and oxygen permeability. The lower encapsulatinginorganic film may include at least one hole filled with an inorganicmaterial different from the inorganic material included in the lowerencapsulating inorganic film.

An upper portion of the components disposed over the substrate 101 is sencapsulated by the flexible encapsulation multilayer 200. A lowerportion of the components disposed over the substrate 101 isencapsulated by the lower encapsulating inorganic film, such as thebuffer film 111, the gate insulating film 121, and the interlayerinsulating film 141. A side portion of the components disposed over thesubstrate 101 is encapsulated by a portion of the lower structure 100which comprises only one or more inorganic materials and which isdisposed between the inorganic surface portion IS and the lowerencapsulating inorganic film. In this manner, a complete inorganicencapsulation structure may be obtained.

The planarization film 161 may comprise an organic material. Aninorganic film formed by a process, such as chemical vapor deposition(CVD), and physical vapor deposition (PVD), is difficult to have a flatupper surface as compared with an organic film formed by a is solutionprocess, such as a spin coating method, and an inkjet coating method.When an inorganic material is used to form the planarization film 161 ofa multilayered structure or a single layered structure, in order toallow the planarization film 161 to have a desired level of flatness, itis disadvantageously required that the height of the planarization film161 should be relatively high. Thus, according to the exemplaryembodiments, it is advantageous that the planarization film 161comprises an organic material. In this case, the organic material may beinterposed between the inorganic surface of the auxiliary upperelectrode 172 and at least one of the buffer film 111, the gateinsulating film 121, and the interlayer insulating film 141. Thus, theinorganic surface portion IS cannot be formed in a region where theplanarization film 161 of the organic material is formed. As a result,according to the exemplary embodiments, the inorganic surface portion ISis disposed relatively lower than the upper surface of the planarizationfilm 161. Here, the term of “being relatively low” includes the meaningthat it is relatively closer to the substrate 101.

The inorganic surface portion IS may have a region divided into aplurality of inorganic surface branches Br1 and Br2 that are spacedapart from each other. The first to fourth peripheral areas PA1, PA2,PA3, and PA4 may include an organic surface portion Os disposed betweenthe inorganic surface branches Br1 and Br2.

The organic surface portion Os may have a protruding shape extendingupwardly. The organic surface portion Os has an upwardly protrudingshape and overlaps with an edge portion of the organic layer 212,thereby increasing the height of the organic layer 212 at the edgeportion of the organic layer 212. Therefore, the flat area FA on thesurface of the second inorganic layer 213 included in the flexibleencapsulation multilayer 200 may be effectively widened. Further, whenthe height of the organic surface portion Os is relatively high, theorganic surface portion Os may function as a dam preventing the organiclayer 212 from being pushed outward (e.g., outwardly of the lowerstructure 100) due to thermal or physical stress applied to the organiclayer 212 of the flexible encapsulation multilayer 200. The organicsurface portion Os and the inorganic surface portion IS will bedescribed later with reference to FIGS. 5 to 10. A touch panel 300 isdisposed on the flexible encapsulation multilayer 200. The touch panel300 includes a plurality of touch electrodes 301, a plurality of touchwires 302 and a plurality of touch terminals 303. A protectiveinsulating film 311 may be disposed on the touch electrodes 301 and thetouch wires 302.

The upper surface of the second inorganic layer 213 of the flexibleencapsulation multilayer 200 has a substantially flat area FA. The touchelectrodes 301 are disposed on the flat area FA. The touch terminals 303are disposed in a touch terminal area 321. The touch wires 302 extend toconnect the touch electrodes 301 to the touch terminals 303 on the flatarea FA.

When the touch electrodes 301 are formed on the flat area FA, touchsensitivity over the entire area of the touch panel 300 may besubstantially uniform, as compared to when the touch electrode 301 isformed on a non-flat area (e.g., uneven area), which may cause uneventhicknesses in the touch electrodes 301.

As used herein, the touch wires 302 being disposed on the flat area FArefers to that all or most of the touch wires 302 being are disposed onthe flat area FA. Further, it may also refer to all or most of theextended sections of one touch wire 302 being disposed on the flat areaFA. For example, the touch wire 302 may be partially located in an areaother than the flat area FA near a point where the touch wire 302 isconnected to the touch terminal 303. The term “most” used herein refersto more than a half.

One touch wire 302 may be connected to one touch electrode 301.Accordingly, as the size of the touch panel 300 increases, the number ofthe touch electrodes 301 may be increased and, thus, the number of thetouch wires 302 may also be increased. When the number of the touchwires 302 is increased, however, the area of the display area DA may bereduced accordingly. As such, the width of the touch wires 302 should bereduced as much as possible. In this case, when the touch wires 302 areformed on the flat area FA, the width of the touch wires 302 may beeasily reduced during the manufacturing process, as compared to when thetouch wires 302 are formed on a non-flat area.

According to the exemplary embodiments, the organic layer 212 of theflexible encapsulation multilayer 200 is disposed to overlap with theflat area FA defined on the second inorganic layer 213. In this case,the upper surface of the second inorganic layer 213 may be madesubstantially flat to form the flat area FA by using the organic layer212 of the flexible encapsulation multilayer 200, without including aseparate organic planarization film between the flexible encapsulationmultilayer 200 and the touch panel 300. Further, even when a separateorganic planarization film is formed between the flexible encapsulationmultilayer 200 and the touch panel 300, since the organic layer 212 theflexible encapsulation multilayer 200 may assist planarization of theorganic planarization film, the thickness of the organic planarizationfilm may be reduced remarkably. Further, even when an inorganicinsulating film having a relatively lower planarization capability thanthe organic planarization film is interposed between the flexibleencapsulation multilayer 200 and the touch panel 300, the substantiallyflat area FA may be formed. Since an inorganic material may provide agreater protection against damage and the like, as compared to anorganic material, the inorganic insulating film may prevent processdamage from the flexible encapsulation multilayer 200 when the touchpanel 300 is directly integrated on the flexible encapsulationmultilayer 200.

A display terminal area 157, in which a plurality of display terminals156 are disposed, is formed in the fourth peripheral area PA4 of thelower structure 100. The display terminals 156 may supply an electricsignal or power for driving the electroluminescent unit EU disposed inthe display area DA. The display terminals 156 disposed in the displayterminal area 157 are in electrical contact with a display externalcircuit board 340. The display external circuit board 340 may be aflexible printed circuit board (FPCB).

Further, a semiconductor chip 341 may be disposed on the displayexternal circuit board 340. A drive integrated circuit, and the like maybe integrated in the semiconductor chip 341. If the semiconductor chip341 is disposed on the lower structure 100, the semiconductor chip 341may be broken when the lower structure 100 is folded and unfolded,because the semiconductor chip 341 is not flexible. Thus, according tothe exemplary embodiments, the semiconductor chip 341 is disposed on thedisplay external circuit board 340.

The touch terminals 303 disposed in the touch terminal area 321 are inelectrical contact with a touch external circuit board 330. The touchexternal circuit board 330 may be a flexible printed circuit board.

A polarizing plate 400 may be disposed on the touch panel 300. In thiscase, the display terminal area 157 and the touch terminal area 321 maybe disposed relatively outer than the polarizing plate 400 in a planview. The flexible printed circuit board that may be used as the displayexternal circuit board 340 or the touch external circuit board 330 isattached to a terminal during a process utilizing heat, such as thermalcompression. Therefore, to prevent the polarizing plate 400 from beingdamaged by heat when attaching the flexible circuit board to theterminal, the display terminal area 157 and the touch terminal area 321should be disposed relatively outer than the polarizing plate 400 in aplan view.

The touch terminal area 321 and the display terminal area 157 aredisposed in different areas, as shown in FIGS. 1 and 2, to prevent thedisplay external circuit board 340, and the touch external circuit board330 from being overlapped with each other and damaged in a process offolding, and unfolding the display external circuit board 340, and thetouch external circuit board 330. By forming the touch terminal area321, and the display terminal area 157 in different areas, as shown inFIGS. 1 and 2, such that the display external circuit board 340 and thetouch external circuit board 330 do not overlap each other, the displayexternal circuit board 340 and the touch external circuit board 330 maybe prevented from being contacting each other and being damaged, whenthe display external circuit board 340 and the touch external circuitboard 330 are fixed to the lower surface of the lower structure 100.

According to the exemplary embodiments, the touch panel 300 may bedirectly integrated on the flexible encapsulation multilayer 200. Bydirectly integrating the touch panel 300 on the flexible encapsulationmultilayer 200, alignment errors that may occur when attaching the touchpanel 300 to the flexible encapsulation multilayer 200 may be preventedand the manufacturing cost of the touch panel 300 may be reduced.Further, reduction of light transmittance due to an adhesive, which mayoccur when the touch panel 300 is attached to the flexible encapsulationmultilayer 200 using an adhesive, may be prevented.

As used herein, the term of “directly integrating” refers to parts of acomponent that are formed on the base according to a predeterminedprocess sequence and the component is completed on the base. Forexample, “directly integrating” is different from attaching a componentonto a base after the manufacture of the component is completed. Beforethe touch panel 300 is directly integrated on the flexible encapsulationmultilayer 200, an inorganic insulating film may be integrated on theflexible encapsulation multilayer 200. The inorganic insulating film mayinclude silicon nitride or silicon oxynitride including silicon andnitrogen. The inorganic insulating film may reduce damage to theflexible encapsulation multilayer 200 when the touch panel 300 isdirectly integrated on the flexible encapsulation multilayer 200.

Since the touch panel 300 is directly integrated on the flexibleencapsulation multilayer 200, the direction in which the touch externalcircuit board 330 is attached to the touch terminals 303 in the touchterminal area 321 may be substantially the same as the direction inwhich the display external circuit board 340 is attached to the displayterminals 156 in the display terminal area 157.

Referring to FIG. 1, both the display terminal area 157, in which thedisplay terminals 156 are disposed, and the touch terminal area 321, inwhich the touch terminals 303 are disposed, are disposed in the fourthperipheral area PA4. If the touch terminal area 321 is disposed in thefirst peripheral area PA1 by widening the first peripheral area PA1,such that the display area DA is located at the center of the lowerstructure 100, the second peripheral area PA2 should also be widened atthe same time, which may narrow the display area DA. Therefore,according to the exemplary embodiments, both the display terminal area157 and the touch terminal area 321 are disposed in the fourthperipheral area PA4, as shown in FIG. 2.

Referring to FIG. 2, both the display terminal area 157, in which thedisplay terminals 156 are disposed, and a touch terminal area 321_a, inwhich touch terminals 303_a are disposed, are disposed in the fourthperipheral area PA4. Further, both the display terminal area 157 and thetouch terminal area 321 a may be adjacent to the outside of the lowerstructure 100 in the fourth direction y2. That is, the display terminalarea 157 and the touch terminal area 321_a are disposed adjacent to eachother along the first direction x1 or the second direction x2. In thiscase, since the area of the fourth peripheral area PA4 may be relativelynarrower than the fourth peripheral area PA4 shown in FIG. 1, thedisplay area DA may be made wider.

Further, the touch terminal areas 321 and 321_a are disposed in the flatarea FA defined on the second inorganic layer 213. When the touchterminal areas 321 and 321_a are formed in an area other than the flatarea FA, adhesive force between the touch terminals 303 and 303_a andthe touch external circuit boards 330 and 330_a is significantlydecreased and may cause a detachment problem. However, according to theexemplary embodiments, detachment may be avoided by forming the touchterminal areas 321 and 321_a in the flat rea FA.

The display terminals 156 have a greater size than the touch terminals303 and 303_a. The display terminals 156 include a power supplyterminal, and the like. When the electroluminescent unit EU iscurrent-driven, a relatively large amount of power should be stablysupplied. On the other hand, when touch sensing detects a voltagechange, the relatively large power may not be required. Accordingly, thedisplay terminals 156 may have a greater size than the touch terminals303 and 303 a. Further, when the area of the touch terminals 303 and 303a is widened, excessive heat may be applied during the process ofattaching the touch external circuit boards 330 and 330_a, which maycause thermal damage to the organic layer 212 included in the flexibleencapsulation multilayer 200. Thus, it is advantageous to form the areasof the touch terminals 303 and 303_a with relatively small sizes.

The touch wires 302 may extend to overlap the auxiliary upper electrode172 in the cross-sectional view of FIG. 3 and may extend to intersectthe auxiliary upper electrode 172 in a plan view of FIGS. 1 to 3. Byforming the auxiliary upper electrode 172 and the touch wires 302 tooverlap with each other, the area of the first to fourth peripheralareas PA1, PA2, PA3, and PA4 may be minimized. Further, the peripheralcircuit C2 is disposed under the auxiliary upper electrode 172 (e.g.,overlap the auxiliary upper electrode 172 in the cross-sectional view ofFIG. 3). By overlapping the touch wires 302 with the auxiliary upperelectrode 172, a signal influence between the touch wires 302 and theperipheral circuit C2 may be minimized.

Referring to FIG. 2, the flat area FA defined on the second inorganiclayer 213 of the flexible encapsulation multilayer 200 may have aprotruding portion P which is a portion protruding in a directionsubstantially parallel to a direction from the display area DA towardthe display terminal area 157. The touch terminal area 321_a, in whichthe touch terminals 303_a are disposed, is disposed on the protrudingportion P, so that both the display terminal area 157 and the touchterminal area 321_a may be disposed adjacent to the outside of the lowerstructure 100 in the fourth direction y2. In this case, the area of thefourth peripheral area PA4 may be reduced by forming the displayterminal area 157 and the touch terminal area 321_a adjacent to eachother in the first direction x1 or the second direction x2 whilelocating both the display terminal area 157 and the touch terminal area321_a in the fourth peripheral area PA4. As a result, the area of thedisplay area DA may be maximized.

Although the touch terminal areas 321 and 321_a, in which the touchterminals 303 and 303_a are disposed, are illustrated as being disposedon the flat area FA in FIGS. 1 to 3, the inventive concepts are notlimited thereto. More particularly, the touch terminal area 321 may bedisposed on an area other than the flat area FA, which will be describedin more detail with reference to FIGS. 5 to 10.

FIG. 5 is a schematic view showing a display device according to yetanother embodiment of the present disclosure.

Referring to FIG. 5, a display device 1000 b includes the upperelectrode power supply wire 901 electrically connected to the upperelectrode 191 of the electroluminescent unit EU to apply an electricalsignal to the upper electrode 191 and a lower electrode power supplywire 902 electrically connected to the lower electrode 171 of theelectroluminescent unit EU to apply an electrical signal to the lowerelectrode 171. Here, the upper electrode power supply wire 901 mayinclude the bus wire 155 and the auxiliary upper electrode 172.

FIG. 6 is an enlarged view of portion “A” of FIG. 5.

Referring to FIG. 6, the touch wires 302 may be curved without angledportions at the corners of the lower structure 100. That is, the touchwire 302 may extend to form a curvature at the corner of the lowerstructure 100. Accordingly, electric field concentration that may occurwith respect to the touch wire 302 at the corner may be prevented.

The plurality of touch wires 302 extend on the first to fourthperipheral areas PA1, PA2, PA3, and PA4. The touch wires 302 areelectrically connected to auxiliary touch wires 302 s through aplurality of first contacts Cnt1. The touch wires 302 and the auxiliarytouch wires 302 s may be connected to each other to reduce the overallresistance. Also, even when the touch wires 302 are damaged or cut fromrepeatedly bending and restoring the display device 1000_b, a normalelectrical signal may be transmitted through the auxiliary touch wires302 s. The auxiliary touch wires 302 s and the touch wires 302 may beformed on the flat area FA on the second inorganic layer 213. In thiscase, damage to the touch wires 302 and the auxiliary touch wires 302 smay be minimized, as compared to when they are formed on the non-flatarea.

The touch wires 302 may be formed to overlap the upper electrode powersupply wire 901. Therefore, it is possible to prevent the peripheralcircuit C2 disposed below the upper electrode power supply wire 901 frombeing interfered by an electrical signal transmitted through the touchwires 302.

The widths of each of the touch wires 302 disposed in the first tofourth peripheral areas PA1, PA2, PA3, and PA4 may be decreased, as theyare disposed farther away from the display area DA and may be increased,as they are disposed closer to the display area DA. As shown in FIG. 5,the length of the outermost touch wire 302 is relatively longer thanthat of the innermost touch wire 302. When the width of the outermosttouch wire 302 is equal to that of the innermost touch wire 302, thearea of the outermost touch wire 302 may become wider. Therefore, thecapacitance generated with the overlapping upper electrode power supplywire 901 may also be greater in the outermost touch wire 302, which maycause a capacitance difference between the touch wires 302. Therefore,in order to reduce such capacitance difference, the width of the touchwire 302 disposed farther away from the display area DA may be less andthe width of the touch wire 302 disposed closer to the display area DAmay be greater, as shown in FIG. 6.

Further, the touch wires 302 may be disposed to overlap the lowerelectrode power supply wire 902. Since a signal of the upper electrode191 may affect the touch wires 302 when the touch wires 302 are disposedto overlap only the upper electrode power supply wire 901, the touchwires 302 may be disposed to overlap the lower electrode power supplywire 902 as well as the upper electrode power supply wire 901 tominimize an excessive signal influence by the upper electrode powersupply wire 901.

An upper electrode power supply terminal 901 t, a lower electrode powersupply terminal 902 t, and the touch terminals 303 are respectivelydisposed at the end of the upper electrode power supply wire 901, theend of the lower electrode power supply wire 902, and the ends of thetouch wires 302. Here, each of the upper electrode power supply terminal901 t and the lower electrode power supply terminal 902 t may be onetype of the display terminals 156 described above (see FIGS. 1 and 2).When the electroluminescent unit EU is current-driven, the upperelectrode power supply terminal 901 t and the lower electrode powersupply terminal 902t should stably supply a relatively large power, ascompared to the power supplied to the touch terminals 303. On the otherhand, when touch sensing detects a voltage change, applying a largepower to the touch terminals 303 may not be required. As such, the sizeof the upper electrode power supply terminal 901 t and the lowerelectrode power supply terminal 902 t may be formed to be relativelygreater than the size of the touch terminals 303. That is, the size ofthe touch terminals 303 may be formed to be relatively less than thesize of the upper electrode power supply terminal 901 t and the lowerelectrode power supply terminal 902i t.

Further, as shown in FIG. 5, by placing the touch terminals 303 betweenthe lower electrode power supply terminal 902 t and the upper electrodepower supply terminal 901 t, signal interference that may occur betweenthe lower electrode power supply terminal 902 t and the upper electrodepower terminal 901 t that are disposed close to each other may beprevented. That is, the upper electrode power supply terminal 901 t, thetouch terminals 303, the lower electrode power supply terminal 902 t aresequentially disposed along the first direction x1 or the seconddirection x2, thereby minimizing signal interference between thesecomponents. Of course, if necessary, terminals for transmitting othertypes of signals may be additionally disposed between the touchterminals 303 and the lower electrode power supply terminal 902 t orbetween the touch terminals 303 and the upper electrode power supplyterminal 901 t.

The upper electrode power supply terminal 901 t, the touch terminals303, and the lower electrode power supply terminal 902 t may be disposedin one direction (e.g., the first direction x1). Further, the lowerelectrode power supply terminal 902 t, the touch terminals 303, and theupper electrode power supply terminal 901 t may be in contact with andelectrically connected to one external circuit board (not shown), suchas a flexible printed circuit board.

The first to fourth peripheral areas PA1, PA2, PA3, and PA4 may have abendable area BA disposed between the display area DA and at least oneof the lower electrode power supply terminal 902 t, the upper electrodepower supply terminal 901 t, and the touch terminals 303.

In order to easily bend the bendable area BA, the touch wires 302 maynot be disposed to overlap or intersect the upper electrode power supplywire 901 and the lower electrode power supply wire 902 within thebendable area BA. Further, the auxiliary touch wires 302 s may not beformed in the bendable area BA.

By bending the bendable area BA, the external circuit board connected tothe at least one of the lower electrode power supply terminal 902 t, theupper electrode power supply terminal 901 t, and the touch terminals 303may be fixed to the back surface of the display device 1000_b.

The lower electrode power supply wire 902, the upper electrode powersupply s wire 901, and the touch wires 302 may include a conductivebridge 902 b, a conductive bridge 901 b, and a conductive bridge 302 b,respectively. The conductive bridges 902 b, 901 b, and 302 b may havecontacts Cnt2 and pass through the bendable area BA. The conductivebridges 902 b, 901 b, and 302 b may be formed in a different layer fromthe touch wires 302, the upper electrode power supply wire 901, and thelower electrode power supply wire 902 adjacent to the conductive bridges902 b, 901 b, and 302 b. The conductive bridges 902 b, 901 b, and 302 bmay assist the bendable area BA bend more easily.

Although not illustrated in the figures, by making the sum of thethicknesses of the insulating layers in the bendable area BA relativelyless than the sum of the thicknesses of the insulating layers inportions of the first to fourth peripheral areas PA1, PA2, PA3, and PA4adjacent to the bendable area BA, the bendable area BA may be bent moreeasily.

The first to fourth peripheral areas PA1, PA2, PA3, and PA4 have theinorganic surface portion IS having a closed shape contiguouslysurrounding the display area DA. FIG. 7 is an enlarged view of area “B”of FIG. 5. Referring to FIG. 7, the inorganic surface portion IS has aregion divided into first to fifth inorganic surface branches Br1, Br2,Br3, Br4, and Br5, which are spaced apart from each other. The first tofourth peripheral areas PA1, PA2, PA3, and PA4 may include first tofourth organic surface portions Os1, Os2, Os3, and Os4 disposed betweenthe first to fifth inorganic surface branches Br1, Br2, Br3, Br4, andBr5. Specifically, the first to fourth peripheral areas PA1, PA2, PA3,and PA4 include the first organic surface portion Os1 disposed betweenthe first and second inorganic surface branches Br1 and Br2, the secondorganic surface portion Os2 disposed between the second and thirdinorganic surface branches Br2 and Br3, the third organic surfaceportion Os3 disposed between the third and fourth inorganic surfacebranches Br3 and Br4, and the fourth organic surface portion Os4disposed between the fourth and fifth inorganic surface branches Br4 andBr5.

Since the structure of the first to fourth organic surface portions Os1,Os2, Os3, and Os4 is similar to that of the organic surface portion Os(see FIG. 4), a description thereof will be omitted to avoid redundancy.

The first to fourth organic surface portions Os1, Os2, Os3, and Os4 arecompletely surrounded by the inorganic-inorganic direct bonding betweenthe lower surface of the flexible encapsulation multilayer 200 and theinorganic surface portion IS in a plan view. The first to fourth organicsurface portions Os1, Os2, Os3, and Os4 absorb and hold impuritiesmoving along an interface between the lower surface of the flexibleencapsulation multilayer 200 and the inorganic surface portion IS in aplan view, thereby reducing the concentration of impurities existing atthe interface between the lower surface of the flexible encapsulationmultilayer 200 and the inorganic surface portion IS. Therefore, thebonding force of the inorganic-inorganic direct bonding may beincreased.

When the impurities disposed at the interface formed by theinorganic-inorganic direct bonding between the lower surface of theflexible encapsulation multilayer 200 and the inorganic surface portionIS are relatively far away from the first to fourth organic surfaceportions Os1, Os2, Os3, and Os4, the impurities may be concentrated on aportion of the interface between the lower surface of the flexibleencapsulation multilayer 200 and the inorganic surface portion IS beforemoving to the first to fourth organic surface portions Os1, Os2, Os3,and Os4 to decrease the bonding force of the inorganic-inorganic directbonding. In addition, the impurities may move to the display area DAbefore moving to the first to fourth organic surface portions Os1, Os2,Os3, and Os4 to deteriorate an intermediate layer included in theelectroluminescent unit EU of the display area DA.

The concentration of the impurities at a portion of the interface or themovement of the impurities to the display area DA may occur morefrequently when the display area DA has a flexible portion that issubjected to repeated bending (or folding) and restoring actions. Inthis case, the first to fourth organic surface portions Os1, Os2, Os3,and Os4 may reduce the concentration of the impurities. As used herein,a flexible portion of the display area may refer to that the displaydevice may be used as a bendable display device, a foldable displaydevice, a rollable display device, a stretchable display device, or aflexible display device. Furthermore, even when the display area DA doesnot have the flexible portion, in a rigid display device employing theflexible encapsulation multilayer 200, the impurities may beconcentrated at a certain portion of the interface or the movement ofthe impurities to the display area DA may occur. Even in this case, theorganic surface portions Os1, Os2, Os3, and Os4 may reduce theconcentration of the impurities. That is, the exemplary embodiments areapplicable to a flat rigid display device in which the flexibleencapsulation multilayer 200 is fixed to a flat and rigid window and acurved rigid display device in which the flexible encapsulationmultilayer 200 is fixed to a curved and rigid window.

Therefore, in order to make the impurities disposed at the interfaceformed by the inorganic-inorganic direct bonding closer to the first tofourth organic surface portions Os1, Os2, Os3, and Os4, the first tofourth organic surface portions Os1, Os2, Os3, and Os4 may have a shapesurrounding or substantially surrounding the display area DA. As usedherein, the term of “surrounding” or “substantially surrounding” refersto contiguously surrounding or discontiguously surrounding.

Specifically, referring to FIG. 5, the first to fourth organic surfaceportions Os1, Os2, Os3, and Os4 contiguously surround the display areaDA. Referring to FIG. 9, first to fourth organic surface portions Os1_c,Os2_c, Os3_c, and Os4_c discontiguously surround the display area DA.Referring to FIG. 11, first to third organic surface portions Os1_d,Os2_d, and Os3_d discontiguously surround the display area DA and afourth organic surface portion Os4_d contiguously surrounds the displayarea DA, so that the first to fourth organic surface portions Os1_d,Os2_d, Os3_d, and Os4_d surround or substantially surround the displayarea DA. Referring to FIG. 12, first to third organic surface portionsOs1_e, Os2_e, and Os3_e discontiguously surround the display area DA anda fourth organic surface portion Os4_e contiguously surrounds thedisplay area DA, so that the first to fourth organic surface portionsOs1_e, Os2_e, Os3_e, and Os4_e surround or substantially surround thedisplay area DA.

If the display area DA has two or less outer sides (e.g., a circle, anellipse, or a semicircle), the first to fourth organic surface portionsOs1, Os2, Os3, and Os4 may contiguously or discontiguously surround thedisplay area DA, such that the organic surface portions Os1, Os2, Os3,and Os4 extend contiguously or discontiguously to correspond to at leastone quarter of the entire outer periphery of the display area DA. If thedisplay area DA has a triangular shape, organic surface portions maycontiguously or discontiguously surround the display area DA, such thatthe organic surface portions extend contiguously or discontiguously tocorrespond to at least one outer side of the display area DA. Further,if the display area DA has a shape, such as square, pentagon, andhexagon, organic surface portions may contiguously or discontiguouslysurround the display area DA, such that that the organic surfaceportions (not shown) extend contiguously or discontiguously tocorrespond to at least two outer sides of the display area DA.

Referring to back FIG. 5, since the first to fourth organic surfaceportions Os1, Os2, Os3, and Os4 are completely surrounded by theinorganic-inorganic direct bonding in a plan view, the first to fourthorganic surface portions Os1, Os2, Os3, and Os4 are isolated from (or donot communicate with) the outside of the display device 1000_b.Therefore, moisture and impurities from the outside of the displaydevice 1000_b may be prevented from infiltrating to the interface formedby the inorganic-inorganic direct bonding between the inorganic surfaceportion IS and the lower surface of the flexible encapsulationmultilayer 200, through the first to fourth organic surface portionsOs1, Os2, Os3, and Os4.

The first organic surface portion Os1, the second organic surfaceportion Os2, the third organic surface portion Os3, or the fourthorganic surface portion Os4 may have a shape that protrudes upward in across-sectional view. Further, in a plan view, the first organic surfaceportion Os1, the second organic surface portion Os2, the third organicsurface portion Os3, or the fourth organic surface portion Os4 may havevarious shapes, such as an island shape, and a shape extending along theextending direction of the first to fifth inorganic surface branchesBr1, Br2, Br3, Br4, and Br5.

The height of the first organic surface portion Os1, the second organicsurface portion Os2, the third organic surface portion Os3, or thefourth organic surface portion Os4 may be substantially the same as theheight of the pixel defining layer 181. Although not illustrated in thefigures, the height of the pixel defining layer 181 may include theheight of a spacer protruding upward from the top of the pixel defininglayer 181.

As one example, the height of the first organic surface portion Os1 maybe substantially equal to the height of the pixel defining layer 181. Inthis case, the first organic surface portion Os1 may be used as aspacer, which contacts an evaporation mask during a vacuum evaporationprocess for forming an intermediate layer of the electroluminescent unitEU. Specifically, when a hole injection layer (HIL), a hole transportlayer (HTL), an electron injection layer (EIL), an electron transportlayer (ETL), and the like included in the intermediate layer are formedas a common layer, the first organic surface portion Os1 havingsubstantially the same as the height of the pixel defining layer 181 maybe used as a spacer of an open evaporation mask. Further, since thefirst organic surface portion Os1 has a substantially closed loop shapethat contiguously surrounds the display area DA, the entire edge of theevaporation mask may correspond to the entire first organic surfaceportion Os1. Therefore, during the evaporation process, the organicmaterials passing through the evaporation mask may be prevented fromescaping to the outside from an internal space defined by theevaporation area of the lower structure 100, the first organic surfaceportion Os1, and the evaporation mask. Further, the first organicsurface portion Os1 may also be used as a spacer for forming the upperelectrode 191 when the upper electrode 191 is formed by a vacuumevaporation process and has a common film structure.

In the first to fourth peripheral areas PA1, PA2, PA3, and PA4, aportion of the flexible encapsulation multilayer 200 including theorganic layer 212 has a relatively greater height and a portion of theflexible encapsulation multilayer 200 not including the organic layer212 has a relatively less height. As such, a height difference occursbetween the portions of the flexible encapsulation multilayer 200. Theheight difference may deteriorate the thickness uniformity of the touchwires 302 when the touch wires 302 are formed and may cause breakage ofthe touch wires 302. Therefore, according to exemplary embodiments, thefirst organic surface portion Os1, the second organic surface portionOs2, the third organic surface portion Os3, or the fourth organicsurface portion Os4 may be formed to have a shape protruding in adirection perpendicular to the plane on which the substrate 101 isdisposed and the protruding shape may be disposed adjacent to the edgeof the organic layer 212 or the outer periphery of the s organic layer212 included in the flexible encapsulation multilayer 200 in the firstto fourth peripheral areas PA1, PA2, PA3, and PA4. As such, the heightdifference between the portions of the flexible encapsulation multilayer200 may be reduced. Thus, the non-uniformity in the thickness of thetouch wires 302 and the breakage of the touch wires 302 may be reduced.A further explanation will be given with reference to FIG. 8.

FIG. 8 is an enlarged view of area “C” of FIG. 5.

Referring to FIG. 8, the innermost first organic surface portion Os1 maybe disposed to cover a boundary where the bus wire 155 and the auxiliaryupper electrode 172 overlap each other. Thus, defects that may occur dueto a step generated between the bus wire 155 and the auxiliary upperelectrode 172 may be minimized by the first organic surface portion isOs1 disposed at the innermost side. Further, the second organic surfaceportion Os2 disposed second from the innermost side may be disposed tocover the outer edge of the bus wire 155. Thus, defects due to a stepformed in the outer edge of the bus wire 155 may be minimized by thesecond organic surface portion Os2 disposed second from the innermostside.

FIG. 9 is a schematic view showing an exemplary embodiment of a displaydevice constructed according to the principles of the invention.

As shown in FIG. 9, the first organic surface portion Os1_c may have asubstantially open loop shape which is opened by at least one firstopening Op1_c to discontiguously surround the display area DA. Thesecond organic surface portion Os2_c may have a substantially open loopshape which is opened by at least one second opening Op2_c todiscontiguously surround the display area DA. The third organic surfaceportion Os3_c may have a substantially open loop shape which is openedby at least one third opening Op3_c to discontiguously surround thedisplay area DA. The fourth organic surface portion Os4_c may have asubstantially open loop shape which is opened by at least one fourthopening Op4_c to discontiguously surround the display area DA.

When the first to fifth inorganic surface branches Br1, Br2, Br3, Br4,and Br5 included in the inorganic surface portion IS are not connectedto each other, the lower surface of the flexible encapsulationmultilayer 200 may be detached from at least one of the first to fifthinorganic surface branches Br1, Br2, Br3, Br4, and Br5 when excessivephysical stress is applied to a display device 1000_c. However,according to exemplary embodiments, since the inorganic surface branchesBr1, Br2, Br3, Br4, and Br5 are connected to each other by the first tofourth openings Op1_c, Op2_c, Op3_c, and Op4_c, the above-describedproblem may be solved.

FIG. 10 is a schematic view illustrating the inorganic surface portionIS shown in FIG. 9. Referring to FIG. 10, the inorganic surface portionIS includes a first region IS1 disposed along the first direction x1, asecond region IS2 disposed along the second direction x2, a third regionIS3 disposed along the third direction y1, and a fourth region IS4disposed along the fourth direction y2 with respect to the display areDA.

Referring to FIGS. 9 and 10, since the first to fourth organic surfaceportions Os1_c, Os2_c, Os3_c, and Os4_c have a substantially open loopshape, the surface of area “K” of the inorganic surface portion IScorresponding to the first to fourth openings Op1_c, Op2_c, Op3_c, andOp4_c does not have organic materials capable of absorbing and removingimpurities. Thus, the impurities disposed at the interface formed by theinorganic-inorganic direct bonding may be concentrated on a portion ofthe interface between the lower surface of the flexible encapsulationmultilayer 200 and the inorganic surface portion IS, which may weakenthe bonding force of the inorganic-inorganic direct bonding.Accordingly, the bonding force of the inorganic-inorganic direct bondingin area “K” may be lowered as compared with other portions having nofirst to fourth openings Op1_c, Op2_c, Op3_c, and Op4_c. Therefore, thewidth of the fourth region IS4 of the inorganic surface portion IS wherearea “K” is disposed is formed relatively greater than the width of thefirst region IS1, the second region IS2, or the third region IS3 of theinorganic surface portion IS where area “K” is not disposed.

As used herein, the width may refer to an average width. Morespecifically, referring to FIG. 9, the width of the first region IS1 maybe a value obtained by dividing the area of the first region IS1 in aplan view by a first length L1. The width of the second region IS2 is avalue obtained by dividing the area of the second region IS2 in a planview by the first length L1. The width of the third region IS3 is avalue obtained by dividing the area of the third region IS3 in a planview by a second length L2. The width of the fourth region IS4 is avalue obtained by is dividing the area of the fourth region IS4 in aplan view by the second length L2.

FIG. 11 is a schematic view showing an exemplary embodiment of a displaydevice constructed according to the principles of the invention.

Referring to FIG. 11, the lower structure 100 of a display device 1000_dincludes the first to third organic surface portions Os1_d, Os2_d, andOs3_d having a shape forming a substantially open loop and the fourthorganic surface portion Os4_d having a shape forming a substantiallyclosed loop. That is, the lower structure 100 may include both the firstto third organic surface portions Os1_d, Os2_d, and Os3_d having asubstantially open loop shape and the fourth organic surface portionOs4_d having a substantially closed loop shape.

FIG. 12 is a schematic view showing an exemplary embodiment of a displaydevice constructed according to the principles of the invention.

Referring to FIG. 12, while the first to third organic surface portionsOs1_e, Os2_e, and Os3_e included in the lower structure 100 of a displaydevice 1000_e are completely surrounded by the direct bonding betweenthe lower surface of the flexible encapsulation multilayer 200 and theinorganic surface portion IS in a plan view, the fourth organic surfaceportion Os4_e may be disposed to be only partially surrounded by theinorganic-inorganic direct bonding in a plan view. That is, the fourthorganic surface portion Os4_e may communicate with the outside of thedisplay device 1000_e.

That is, the lower structure 100 according to the illustrated embodimentmay include the fourth organic surface portion Os4_e having asubstantially closed loop shape communicating with the outside and thefirst to third organic surface portions 0s1_e, Os2_e, and Os3_e whichare disposed between the display area DA and the fourth organic surfaceportion 0s4_e. Here, the first to third organic surface portions Os1_e,Os2_e, and Os3_e have is substantially open loop shapes and completelysurrounded by the direct bonding between the lower surface of theflexible encapsulation multilayer 200 and the inorganic surface portionIS in a plan view.

In this case, the height of the fourth organic surface portion Os4_ecommunicating with the outside may be substantially the same as that ofthe pixel defining layer 181 and may function as a spacer for theevaporation mask. By making the height of the first to third organicsurface portions Os1_e, Os2_e, and Os3_e, which do not communicate withthe outside, relatively lower than the height of the fourth organicsurface portion Os4_e communicating with the outside, the width of thefirst to third organic surface portions Os1_e, Os2_e, and Os3_e, whichdo not communicate with the outside, is effectively lowered to narrowthe width of the first to fourth peripheral areas PA1, PA2, PA3, andPA4.

Meanwhile, the first and second organic surface portions Os1_e and Os2_emay extend to cover a side portion of a conductive multilayer. Since theside portion of the conductive multilayer is vulnerable to corrosionbecause a large number of interfaces are exposed, the first and secondorganic surface portions Os1_e and Os2_e may prevent the corrosion ofthe conductive multilayer by covering the side portion of the conductivemultilayer. Further, the first and second organic surface portions Os1_eand Os2_e may absorb and hold impurities, such as moisture and oxygen,which may flow out from the interfaces exposed at the side portion ofthe conductive multilayer.

For example, the conductive multilayer is the auxiliary upper electrode172 which is the same film as the lower electrode 171 of theelectroluminescent unit EU and a side portion of the auxiliary upperelectrode 172 may be covered by the first organic surface portion Os1_edisposed at the innermost side in FIG. 12. In this case, the auxiliaryupper electrode 172 may include a first conductive indium tin oxidefilm, a silver (Ag) film on the first conductive indium tin oxide film,and a second conductive indium tin oxide film on the silver film.

For example, the conductive multilayer may be the bus wire 155 which isthe same film as the source electrode 156 a or the drain electrode 156 bof the pixel thin film transistor (PC-TFT) and the side portion of thebus wire 155 may be covered by the second organic surface portion Os2_edisposed second from the innermost side in FIG. 12. The bus wire 155 maybe the same film as the source electrode 156 a or the drain electrode156 b of the pixel thin film transistor (PC-TFT). In this case, the buswire 155 may include a first titanium (Ti) film, an aluminum (Al) filmon the first titanium film, and a second titanium film on the aluminumfilm or may include a first molybdenum (Mo) film, an aluminum film onthe first molybdenum film, and a second molybdenum film on the aluminumfilm.

Although certain exemplary embodiments and implementations have beendescribed herein, other embodiments and modifications will be apparentfrom this description. Accordingly, the inventive concepts are notlimited to such embodiments, but rather to the broader scope of thepresented claims and various obvious modifications and equivalentarrangements.

What is claimed is:
 1. An electroluminescent device comprising: a lowerstructure which has an emission area and a peripheral area surroundingthe emission area, and which comprises an insulation film and anelectroluminescent unit having a lower electrode disposed on theinsulation film, an intermediate film disposed on the lower electrode,and an upper electrode disposed on the intermediate film, a flexibleencapsulation multilayer disposed on the emission area and theperipheral area of the lower structure, and including at least threelayers, and a touch panel disposed on the flexible encapsulationmultilayer, and having a touch electrode, wherein the peripheral areaincludes a lower electrode power supply terminal, a lower electrodepower supply wire electrically connecting the lower electrode to thelower electrode power supply terminal, an upper electrode power supplyterminal, an upper electrode power supply wire electrically connectingthe upper electrode to the upper electrode power terminal, a touchterminal, and a touch wire electrically connecting the touch electrodeto the touch terminal, wherein the flexible encapsulation multilayerincludes a lower surface comprising only one or more inorganicmaterials, wherein the peripheral area includes an inorganic surfaceportion substantially surrounding the emission area, disposed outsidethe upper electrode in a plan view, and comprising only one or moreinorganic materials, wherein an entire of the inorganic surface portiondirectly contacts the lower surface of the flexible encapsulationmultilayer, wherein the lower structure includes a lower encapsulatinginorganic film horizontally expanding below a surface of the lowerstructure to vertically correspond to the emission area and theperipheral area, and a portion of the lower structure disposed betweenthe lower encapsulating inorganic film and the entire of the inorganicsurface portion comprises only one or more inorganic materials, andwherein the touch wire comprises a first portion overlapping the lowerelectrode power supply wire and a second portion overlapping the upperelectrode power supply wire.
 2. The electroluminescent device of claim1, wherein the upper electrode power supply wire includes an auxiliaryupper electrode extending along a periphery of the emission area toelectrically contact a bottom surface of the upper electrode, whereinthe lower structure further comprises a peripheral circuit disposedunder the auxiliary upper electrode in the peripheral area, and whereina portion of the touch wire extends substantially along the periphery ofthe emission area and overlaps both the auxiliary upper electrode andthe peripheral circuit.
 3. The electroluminescent device of claim 2,wherein widths of the portions of the touch wires decrease in adirection away from the emission area.
 4. The electroluminescent deviceof claim 2, wherein the peripheral area further includes an auxiliarytouch wire electrically connected to the touch wire and overlapping theportion of the touch wire.
 5. The electroluminescent device of claim 2,wherein at least one of the lower electrode power supply terminals, atleast one of the touch terminals, and at least one of the upperelectrode power supply terminals are disposed in a terminal area of theperipheral area, wherein the peripheral area includes a bendable areaextending between the emission area and the terminal area, wherein atleast one of the lower electrode power supply wire, the upper electrodepower supply wire, and the touch wire includes a conductive bridge fortransmitting an electrical signal through the bendable area, and whereinthe conductive bridge is formed in a different layer from the at leastone of the lower electrode power supply wire, the upper electrode powersupply wire, and the touch wire including the conductive bridge.
 6. Theelectroluminescent device of claim 1, wherein the touch wire furthercomprises a third portion overlapping the upper electrode power supplywire, and wherein the first portion of the touch wire is disposedbetween the second and third portions of the touch wire.
 7. Theelectroluminescent device of claim 6, wherein the third portion of thetouch wire overlaps an end portion of the upper electrode power supplywire.
 8. The electroluminescent device of claim 1, wherein the lowerelectrode is disposed directly on a top surface of the insulation film,and the entire of the inorganic surface portion is disposed to berelatively lower than the top surface of the insulation film, whereinthe inorganic surface portion has at least a region including aplurality of inorganic surface branches which are spaced apart from eachother, wherein the peripheral area further includes an organic surfaceportion which is disposed between the inorganic surface branches, whichcomprises an organic material, which substantially surrounds theemission area, and which is substantially surrounded in a plan view by adirect contact interface between the inorganic surface portion and thelower surface of the flexible encapsulation multilayer, wherein theinorganic surface branches include an outer inorganic surface branchdisposed relatively outer than the organic surface portion and an innerinorganic surface branch disposed relatively inner than the organicsurface portion, wherein the upper electrode power supply wire comprisesa bus wire extending on a top surface of the inorganic insulating filmalong a periphery of the emission area and an auxiliary upper electrodewhich extends on side and top surfaces of the insulation film along theperiphery of the emission area to electrically contact both a topsurface of the bus wire and a bottom surface of the upper electrode,wherein the inner inorganic surface branch includes at least a portionof a top surface of the auxiliary upper electrode to have a heightrelatively greater than a height of the outer inorganic surface branch,and wherein a portion of a surface of the bus wire directly contacts thelower surface of the flexible encapsulation multilayer and the portionof the surface of the bus wire is relatively farther than the organicsurface portion from the emission area.
 9. The electroluminescent deviceof claim 8, wherein the electroluminescent device is capable of beingflexed, bent, folded, rolled, or stretched by an end user.
 10. Theelectroluminescent device of claim 8, wherein the inorganic surfaceportion includes at least two stepped surface portions each including atop surface portion of the inorganic insulating film, a side surfaceportion of the bus wire, and a top surface portion of the bus wire, andwherein the bus wire has an outer edge portion and an inner edge portionopposite to the outer edge portion, the outer edge portion of the buswire is relatively farther than the inner edge portion of the bus wirefrom the emission area, the outer edge portion of the bus wire isdisposed under the bottom surface of the flexible encapsulationmultilayer, and the outer edge portion of the bus wire is not in directcontact with the bottom surface of the flexible encapsulationmultilayer.
 11. The electroluminescent device of claim 10, wherein theinorganic surface portion further includes at least two stepped surfaceportions each including a top surface portion of the inorganicinsulating film, a side surface portion of the auxiliary upperelectrode, and a top surface portion of the auxiliary upper electrode,and wherein the auxiliary upper electrode has an outer edge portion andan inner edge portion opposite to the outer edge portion, the outer edgeportion of the auxiliary upper electrode is relatively farther than theinner edge portion of the auxiliary upper electrode from the emissionarea, the outer edge portion of the auxiliary upper electrode isdisposed under the bottom surface of the flexible encapsulationmultilayer, and the outer edge portion of the auxiliary upper electrodeis not in direct contact with the bottom surface of the flexibleencapsulation multilayer.
 12. The electroluminescent device of claim 10,wherein the inorganic surface portion further includes at least twostepped surface portions each including a top surface portion of the buswire, a side surface portion of the auxiliary upper electrode, and a topsurface portion of the auxiliary upper electrode, and wherein theauxiliary upper electrode has an outer edge portion and an inner edgeportion opposite to the outer edge portion, the outer edge portion ofthe auxiliary upper electrode is relatively farther than the inner edgeportion of the auxiliary upper electrode from the emission area, theouter edge portion of the auxiliary upper electrode is disposed underthe bottom surface of the flexible encapsulation multilayer, and theouter edge portion of the auxiliary upper electrode is not in directcontact with the bottom surface of the flexible encapsulationmultilayer.
 13. The electroluminescent device of claim 10, wherein theinorganic surface portion further includes at least two stepped surfaceportions each including a top surface portion of the inorganicinsulating film, a side surface portion of the auxiliary upperelectrode, and a top surface portion of the auxiliary upper electrode,wherein the inorganic surface portion further includes at least twostepped surface portions each including a top surface portion of the buswire, a side surface portion of the auxiliary upper electrode, and a topsurface portion of the auxiliary upper electrode, and wherein theauxiliary upper electrode has an outer edge portion and an inner edgeportion opposite to the outer edge portion, the outer edge portion ofthe auxiliary upper electrode is relatively farther than the inner edgeportion of the auxiliary upper electrode from the emission area, theouter edge portion of the auxiliary upper electrode is disposed underthe bottom surface of the flexible encapsulation multilayer, and theouter edge portion of the auxiliary upper electrode is not in directcontact with the bottom surface of the flexible encapsulationmultilayer.
 14. The electroluminescent device of claim 8, wherein theportion of the surface of the bus wire, which directly contacts thelower surface of the flexible encapsulation multilayer, is included inthe outer inorganic surface branch.
 15. The electroluminescent device ofclaim 1, wherein at least one of the lower electrode power supplyterminals, at least one of the touch terminals, and at least one of theupper electrode power supply terminals are disposed in a terminal areaof the peripheral area and have substantially the same heights to beelectrically connected to one external circuit board.
 16. Theelectroluminescent device of claim 15, wherein the at least one of thetouch terminals is disposed between the at least one of the lowerelectrode power supply terminals and the at least one of the upperelectrode power supply terminals.
 17. The electroluminescent device ofclaim 15, wherein the peripheral area includes a bendable area extendingbetween the emission area and the terminal area, and wherein the touchwire does not overlap the lower electrode power supply wire and theupper electrode power supply wire in the bendable area.
 18. Theelectroluminescent device of claim 15, wherein a size of the touchterminal is relatively less than a size of the lower electrode powersupply terminal or a size of the upper electrode power supply terminal.19. The electroluminescent device of claim 1, wherein at least one ofthe lower electrode power supply terminal and the upper electrode powersupply terminal is disposed in a power terminal area of the peripheralarea and electrically connected to a first external circuit board,wherein the touch terminal is disposed in a touch terminal area of theperipheral area and electrically connected to a second external circuitboard, wherein the power terminal area and the touch terminal area aredisposed at a side of the lower structure and do not overlap each otherin a plan view, wherein the first external circuit board and the secondexternal circuit board are disposed at the side of the lower structureand do not overlap each other in a plan view, wherein a direction inwhich the first external circuit board is attached to the at least oneof the lower electrode power supply terminal and the upper electrodepower supply terminal is the same as a direction in which the secondexternal circuit board is attached to the touch terminal, wherein theflexible encapsulation multilayer includes a first inorganic layer, anorganic layer disposed on the first inorganic layer, and a secondinorganic layer disposed on the organic layer, and wherein the touchterminal area does not overlap the organic layer in a plan view.
 20. Theelectroluminescent device of claim 1, wherein at least one of the lowerelectrode power supply terminal and the upper electrode power supplyterminal is disposed in a power terminal area of the peripheral area tobe electrically connected to a first external circuit board, wherein thetouch terminal is disposed in a touch terminal area of the peripheralarea to be electrically connected to a second external circuit board,wherein the power terminal area and the touch terminal area are disposedat a side of the lower structure and do not overlap each other in a planview, wherein the first external circuit board and the second externalcircuit board are disposed at the side of the lower structure and do notoverlap each other in a plan view, wherein a direction in which thefirst external circuit board is attached to the at least one of thelower electrode power supply terminal and the upper electrode powersupply terminal is opposite to a direction in which the second externalcircuit board is attached to the touch terminal, wherein the flexibleencapsulation multilayer includes a first inorganic layer, an organiclayer disposed on the first inorganic layer, and a second inorganiclayer disposed on the organic layer, and wherein the touch terminal areadoes not overlap the organic layer in a plan view.